Might it derive from the name of a battery position or other field work named after an officer, that had been incoprorated into the siege works? The phonetic rendering of a French name, for instance, might explain the exotic aspect.
EDIT: On reflection, if it's two Boyzoes the above suggestion is less likely to be an explanation. The contraction of a military term seems more likely, although there are no guiding apostrophes to help.
Last edited by jf42
on 23 Oct 2016 14:32, edited 1 time in total.